Bonekickers

History behind ‘The Eternal Fire’: Quintanus’s explosives

Saltpeter or potassium nitrate is the basic ingredient of gunpowder, which acts as an oxidizing agent. It can occur naturally through the breakdown of organic material by bacteria, and dissolves in water. Bat guano is a particularly good source.

It is commonly found in caves as an effervescent white powder on the rock surface caused by the evaporation of the percolating groundwater. It was often collected from cave walls, and used to make gunpowder. In classical antiquity saltpeter was known about and collected because it was used in cooking and preserving food. However, it is not known whether the Romans understood its combustible qualities, where it needs to be mixed with a fuel like charcoal, in order to generate an explosion.